How many shingles do i need for a 20×20 garage | how many bundles of shingles do i need for a 20×20 garage | how to calculate shingles quantity for 20×20 garage.
Calculation of shingles quantity is simple and easy if your garage roof is flat, but majority of house in US have pitch roof that makes calculation of square footage area for pitch roof difficult. The garage footprint is 20×20 = 400 sq ft but the roof surface is quite a bit more due to slope. Gambrel roofs have different slopes and configuration pitch but generally the roof surface is roughly twice the footprint in square footage.
This article describes the basic maths calculation to calculate roof materials such as shingles. If you have ever question yourself “how many squares footage or square is my garage roof?” this article will help you find the square footage of your garage roof. This article describe about the maths formula to figure out how much shingles you need to order.
When you talked Roofing is about using the term “square”, a “square” equal to 100 square feet of roof or a 10 foot by 10 foot area. So a roof that has 200 square feet of area has 2 squares. Remember that unless the roof is flat, the square footage of the building is different than the square footage of the roof because of the slope or pitch of the roof and the overhangs.
Eves overhangs can vary from a few inches to a few feet depending on requirements; however, it is suggested width of an overhang is between 12” and 18” for eaves and no more than 8” for rakes. That said, overhangs can extend as far as 2′ without the need for external supports. In this article we assume 2 feet overhang in both dimensions.
How do you calculate the square footage of 20×20 garage roof
Figure out the area of the garage roof plus the overhangs:- determine the squre footage of the garage foot print by measuring the length and width of the garage including the overhangs. Assume the overhangs are 1 feet both sides eves and rake then you have 2 feet extra, so each dimension for 20×20 shed roof with overhangs is around 22’×22′ = 484 square footage.
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Find the roof pitch or slope:- the roof pitch is the amount of slope. The slope is described by the “rise” in inches or how far up it goes over the “run” in inches or how far horizontal it goes. We will use a 6 in 12 pitch. For every 6 inches the roof goes up to the peak it goes 12 inches horizontally.
Calculate the square of rise and run and sum it:- square of rise 6×6=36, square of run = 12×12 = 144, add both 36 +144 = 180.
Find the square root of the sum:- square root of 180 = 13.417
Sum divide by 12 to get the product:- square root of 180 = 13.417 is divided by 12 as 13.417 ÷ 12 = 1.118, hence 1.118 equals the product
Multiply the product by the flat roof area and divide by 100:- our 20×20 garage roof square footage with overhangs is 484 square feet, so 1.118 x 484 = 541 square feet, 541 / 100 = 5.41 squares.
Add 10% for wastes:- wastages 10% of 5.41 squares = 0.541, so final squares of shingles do you need = 5.41+ 0.541 = 5.951 squares, it is rounded to 6 squares.
How many shingles do i need for a 20×20 garage
As a rule of thumb, there are 3 bundles of shingles required to a square or 100 sq ft of roof surface area. There are also 26 standard-sized asphalt shingles (three-tab strip shingles) in each bundle. Depending on the shingle manufacturer, the number of shingles in a bundle can vary widely.
For traditional asphalt 3-tab roof shingles, there are 26 pieces in a bundle. Architectural shingles will have around 21 shingles per bundle for similar square footage, as they are larger than standard 3-tab shingles. So, number of shingles are not uniform, it depends on size and type of shingles.
A square of shingles is the number of shingles needed to cover 100 sq feet of roof area. However, shingles are packaged in a way that they are light enough for the average person to carry around. When shingles come three bundles to the square, there are 26 standard-sized shingles in each bundle.
Asphalt shingles and most other roof shingles are typically available in bundles. For each roofing square or 100 sq ft, you will need three bundles of shingles. The average size of 20×20 garage roof is 6 squares, which typically requires 18 bundles of three-tab asphalt shingles or any other starter strips.
Typically for a 20×20 garage roof you will need about 6 squares or 18 bundles or 468 pieces of three tab strip standard size asphalt shingles if the overhang is 1 foot and the roof pitch is 6/12. So to cover a 20×20 garage roof you will need 18 bundles or 468 pieces of shingle or 6 squares of roofing material.
How many bundles of shingles do i need for a 20×20 garage
For a 20×20 garage roof, on average, you will need 18 bundles of three tab strip standard-sized asphalt shingles when overhangs is 1 feet and roof slope is 6/12. For each roofing square, you will need three bundles of shingles, so for 6 square = 3× 6 = 18 bundles.
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How many squares of shingles do i need for a 20×20 garage
As per rule of thumb, for a 20×20 garage roof, you will need approximately 6 squares of 3- tab strip standard-sized Asphalt shingles or when overhangs is 1 feet and roof slope is 6/12.
Note:- Be aware, the only way to get a 100 percent accurate measurement is to have a local roofing contractor come out to professionally measure your garage roof and give you a quote. However, I explained about to get a rough measurement of your garage roof square footage and shingles quantity.
For a 20×20 garage roof, you will need approximately 6 squares or 18 bundles or 468 pieces of three tab strip standard-sized asphalt shingles if overhangs is 1 foot and roof slope is 6/12.